Abstract: A roller brush retainer including a retention structure for preventing a paint roller's tube brush from sliding off the roller. The paint roller includes a handle, a roller, a tube brush, and in one embodiment of the invention the retaining structure includes a retaining groove and a retaining ring. In use, the tube brush is slid onto the roller of a paint roller and the retention structure is mounted on the roller by spring biased action. The retainer means is used to securely and effectively hold the tube brush onto the roller and therefore prevent accidental disengagement and mess.